A wide variety of commercial equipment is available for use in abrading and polishing surfaces, stock removal and the like. The equipment and tools therefor exist in various forms (e.g., rotary, continuous belt, reciprocating, etc.). The rotary devices generally employ wheels or disks of two types, coated or bonded. A coated abrasive is one which the particles of either abrasive or polishing media are present in a thin coating on the surface of a body material which may be paper, cloth, netting, or the like, and are bonded to such body material by a suitable adhesive or binder vehicle. A bonded abrasive is one in which the abrasive is dispersed throughout the bonding vehicle which is preformed into various solid shapes and cured or otherwise solidified for use in solid form. The bonding vehicles used are often polymeric materials. These polymeric materials may be foamed. Some work has been done with "foamed" abrasives in an effort to obtain some degree of yieldability. These efforts have been almost entirely limited to scouring pads, or similar hand-held devices of limited usefulness (note British Pat.No. 716,422). This is because the foam matrix by its very nature is inherently weak as a body material, and is incapable of withstanding the internal forces in use which tend to distort and disintegrate the foamed structure. This is particularly true in the case of wheels employed in high speed rotary operations which may result in ballooning of the wheels or disruptive forces which otherwise render the wheels ineffective for some uses, particularly uses involving high speed stock removal.
Some further attempts have been made to overcome the above difficulties by densifying the foam (note U.S. Pat. No. 2,885, 276) but these efforts have been found to intensity the internal destructive potential in rotary operations, or to produce a wheel so densified so as to be subject to the same difficulties encountered with "bonded" abrasive wheels (i.e., "clogging", "smearing", "chattering", or utility limited to abrading of "high spots", etc.).
Accordingly there is a need for a rotary finishing or abrading tool which has a foamed elastomeric bond of relatively low tensile strength that has a cellular structure which provides improved cutting action and material removal versus tool life, while also providing shapeability, shape containment, and non-loading or smearing, and non-chatter characteristics.